3. Define the term 'variable'. What is the difference between qualitative and quantitative variables?

Basic to the idea of measurement is the concept of 'variable.' As in ordinary speech, the concept of a variable implies that things exist in amounts of more or less, or occur with greater or lesser frequency. A formal definition of a variable is that it is an object or event wnicn can change over time, or it refers to two objects of the same class which can differ.

Whether all phenomena in the world exist in amounts that are measurable, there appear to be, at any one time, some variables that defy quantification. Such variables are called 'qualitative' variables to distinguish them from the 'quantitative' variables that may be measured in a fashion analogous to that which is used in the physical sciences. Quantitative variables differ in degree while qualitative variables differ in kind. Current examples of variables that appear to be qualitative variables might include sex, religion, and marital status. Unable to measure these variables, we simply classify people as males, Protestants, married, and so on. Among the many possible quantitative variables, we might include income, population size, birth rate, and so on. These variables can be measured and can be expressed in terms of numbers.

The distinction between qualitative and quantitative variables is important. The researcher must determine which kind of variables he is dealing with because the statistical techniques available for use depend upon the nature of the variables under study. He must use the most powerful techniques appropriate for his particular problem.

Social scientists attempt to put the foregoing material concerning measurement and quantitative and qualitative variables into perspective by distinguishing among four levels of measurement, ranging from the crudest and least quantitative to the most rigorous and most completely quantitative. The four levels of measurement are called: nominal, ordinal, interval, and ratio measurement.

Another group maintains that bias is inherent in all thought and action; that the very choice of topics upon which to do research reflects the biases of the researcher. They argue, further, that sociologists, as scientists and as citizens, have as much right and as much responsibility as anyone else to say how the knowledge that they accumulate shall be used. Indeed they believe that sociologists, by virtue of their special expertise in the analysis of social problems, often are better qualified than diplomats and administrators to help the society move toward fuller realization of its goals. These sociologists add control to understanding and prediction, as proper goals of their science.

4. What are signs? Why is sign behavior so important to the sociologist?

In addition to, and at a more abstract level than that of gestures, human communication typically involves the use of signs. A sign is simply any object or thing that leads to knowledge of something other than itself. Sign behavior has three basic components: the sign itself; what the sign signifies or stands for; and the observer or interpreter of the sign. All three components are necessary for communication through signs.

Signs may be either natural or conventional signs. It is useful to make a sharp distinction between the two. And it is the use of a type of conventional signs — verbal signs — which makes human communication different from the communication systems of insects and of primates.

Natural signs and conventional signs. In the case of natural signs, there is an inductive relationship between the sign itself and what the sign signifies, that can be discovered through observation, and without the aid of dictionaries or advice from other people. This is possible because the sign and what the sign signifies occur in the same time-space framework. Several examples should clarify the relationship between the natural sign and its referent: smoke signifies combustion; a watch signifies a watchmaker; and clouds signify moisture.

Conventional signs, by contrast, are related to their referents as a result of convention or common usage. The letters, b-o-x, in that sequence stand for a particular material object and do so arbitrarily because people agree upon that particular usage. The letters, b-o-x, theoretically could be used to stand for any other object if people generally agreed to such usage. Similarly, any other combination of letters could have been used to refer to what we refer to as a box.

Symbols. What we have described as conventional signs are also called symbols. The two terms are synonymous.

Symbols are man's most versatile signs. They can signify imaginary objects and events as well as real ones. They may refer to objects and to quite intangible ideas. Symbols standing for concrete objects would include 'dog,' 'pencil,' and 'house.' Symbols standing for ideas would include 'marriage,' 'loyalty,' and 'race.' Symbols standing for imaginary objects would include 'witches,' 'unicorns,' and 'racial superiority.'

From the standpoint of social behavior, man's most important symbols are words. The use of words distinguishes his communication from that of all other species, enriching it so greatly that human communication seems almost a thing apart. Man's humanity is very much tied up with the possession of language.